U.S Sen. David Vitter and U.S. Rep. Bill Cassidy are smart men who clearly know their way around government and politics. So I’m trying to understand their arguments for depriving the people who work for members of Congress, not just members and senior administration officials themselves, of employer-subsidized health coverage.

Really, I am.

I’m trying to understand how, in their minds, receiving the same sort of benefit that millions of Americans enjoyed before Obamacare’s insurance exchanges opened up this week, and still enjoy today, amounts to special treatment. Trying to understand how blocking contributions toward the cost of insuring these people, whom Congress forced off federal employee health insurance and into a system designed to provide coverage for those who don’t get it through an employer, is fair, given that it would amount to a substantial effective pay cut.

I’m trying to understand the sense of urgency Vitter, and now Cassidy, are exuding over the matter, to the point where they’re willing to shut the government down over it. Trying to understand how it’s more pressing than keeping federal workers on the job; making sure Head Start programs are open to provide care, education and often the only nutritious food children get; allowing cancer patients to enroll in clinical trials at the National Institutes of Health; and keeping the country’s monuments, museums and national parks open.

I’m trying to understand what problem the proposal purports to solve, what shortcoming of the Affordable Care Act — and there are plenty to choose from — it might fix.

And I’m trying really hard to understand how the underlying message of their crusade — that participating in the exchanges would be a “burden,” as Cassidy put it in an op-ed published on the Washington website “The Hill” — jibes with the overwhelming interest that’s greeted their opening among the exchanges’ intended customers: people looking to get covered even if they haven’t been able to afford it in the past or have been rejected because they have pre-existing conditions.

And you know what? I’m coming up empty.

Sure, Vitter has been getting some mileage out of the push. He first tried to attach it to a bipartisan energy efficiency bill, succeeding only in stalling the bill’s adoption. His idea then found its way into the frantic maneuvering over the shutdown, as one of several anti-Obamacare measures Republicans tried to tack on to the continuing resolution to keep the government open, when they knew that Democrats and President Barack Obama would accept no such condition.

Cassidy attached his name to the effort Monday with the opinion piece. In it he outlined the legalistic arguments against continuing to help pay for congressional staffers’ insurance.

Cassidy then shifted into rhetorical overdrive, arguing that the idea behind the original provision in the ACA was that, “if Congress is going to write a law that forces tens of thousands of Americans on Obamacare through the individual mandate, Congress should be prepared to share in that experience.”

“The hope must be that when Congress experiences the burden of Obamacare, it will become more sympathetic to American families similarly burdened,” he concluded.

Somehow, all those potential customers who’ve been trying to sign up seem more enthusiastic than burdened, except maybe by the difficulties in getting through to the overtaxed, still-glitchy website — or, in the case of the lowest-income applicants, the discovery that Gov. Bobby Jindal’s refusal to expand Medicaid leaves them ineligible for subsidies available to those who are somewhat better off.

None of this is to say there aren’t some clear benefits to this drive — for the politicians involved, anyway.

Vitter managed to raise his profile with the conservative base, although not to the level of Texas colleague Ted Cruz, who has set a new standard. Cassidy, who’s running for U.S. Senate against Obamacare supporter Mary Landrieu, gets to shore up his right flank and also defuse his past support for a state-level insurance exchange, something Democrats bring up relentlessly.